How to remove Exif Data from RAW files?

tonylong wrote in post #11341408
You might want to get back to us as to what exactly your are trying to do...

Hmmm ... maybe you should read the OP again.

Exactly what he wants to do is "remove exif data from RAW files without converting them to JPG (so the files remain RAW files)." What part of that do you not understand?

Peano wrote in post #11341520
Hmmm ... maybe you should read the OP again.

Exactly what he wants to do is "remove exif data from RAW files without converting them to JPG (so the files remain RAW files)." What part of that do you not understand?

Heh! There may be something specific, not just stripping the entire exif out but maybe deleting just certain fields, which could have different approaches. I'm guessing that he may want to share a Raw file without sharing the exif info, but without him clarifying things a bit, at this point we're all just pretty much mumbling to ourselves and each other!

tonylong wrote in post #11341559
Heh! There may be something specific, not just stripping the entire exif out but maybe deleting just certain fields, which could have different approaches.

It could? OK, show us how it could have different approaches. Show one way to strip any exif data from a raw file. I'd be interested in seeing your approach.

I could probably do it with a hex editor, but it'd take a while.

tim wrote in post #11341648
I could probably do it with a hex editor, but it'd take a while.

We're in no hurry. Go ahead and how how you would do that.

I'd have to spend a bunch of time on google finding the raw file format, at a byte level. I'm not going to because I see no point.

tim wrote in post #11341666
I'd have to spend a bunch of time on google finding the raw file format, at a byte level. I'm not going to because I see no point.

Riiiiiiiiiight.

I've never messed with ExifTools or any other program that alters Raw exif data except I've poke around the Lightroom Time/Date change function and that does have the ability to replace that bit of Exif info in the Raw file itself.

Now, if you recall, the OP asked "Is there a way to remove exif data from RAW files" and that may imply different possibilities than "stripping" exif data per se, for example if there was a way of filling Exif fields replacing the "real" data with "non-data" using one of these tools then that could be considered a way of "removing Exif data" -- you'd be replacing it with basically gibberish. You wouldn't be "stripping" things but removing and replacing data with meaningless stuff.

But, like I said, I haven't worked with Exif modification tools so I was just wondering if it was possible to do any operation without trashing the file -- I wasn't claimaing to "know stuff" except for instructions on how he could trash the file all by himself using the text approach.

tonylong wrote in post #11341688
I've never messed with ExifTools or any other program that alters Raw exif data except I've poke around the Lightroom Time/Date change function and that does have the ability to replace that bit of Exif info in the Raw file itself.

Now, if you recall, the OP asked "Is there a way to remove exif data from RAW files" and that may imply different possibilities than "stripping" exif data per se, for example if there was a way of filling Exif fields replacing the "real" data with "non-data" using one of these tools then that could be considered a way of "removing Exif data" -- you'd be replacing it with basically gibberish. You wouldn't be "stripping" things but removing and replacing data with meaningless stuff.

But, like I said, I haven't worked with Exif modification tools so I was just wondering if it was possible to do any operation without trashing the file -- I wasn't claimaing to "know stuff" except for instructions on how he could trash the file all by himself using the text approach.

I see.

Peano wrote in post #11341682
Riiiiiiiiiight.

I'm not sure what the extra i's are for. All files are just a collection of bytes, if you know which one to change I could make the exif say it was coming from a 1Ds5, with a 1/1000,000,000 shutter speed at ISO500,000. I could have it say it was taken by a toaster. Working out things at the byte level is really time consuming though, especially since you can just convert it to jpeg or tiff and use standard tools.

The OP still hasn't said why they'd want to do this.

The EXIF info is about the first 4000 bytes if you are so inclined to poke around with a hex editor, so it is possible. The question I have to ask is why? You could edit bytes 286-385 and 828-868 if you wanted to modify the date taken, or the bytes after 4054 to edit the lens used.

What are you trying to change again?

Peano wrote in post #11341682
Riiiiiiiiiight.

I have a super-secret RAW file for you. It was shot with a Canon 3D prototype with a new 2000mm f/0.8 USM III lens. Check the EXIF, it's all there in the RAW.

IMG_7679.CR2

tim wrote in post #11341737
The OP still hasn't said why they'd want to do this.

John the Geek wrote in post #11341741
The question I have to ask is why?

Why he wants to do it is irrelevant. Don't confuse the possibility of doing something with the motive for doing it. The OP asked whether it is possible. His motive has no relevance to the question of whether it can be done.

Is it possible to strip the exif data from a jpeg? Sure, and I can show you how without knowing why someone might want to do it.

Peano wrote in post #11341839
Why he wants to do it is irrelevant. Don't confuse the possibility of doing something with the motive for doing it. The OP asked whether it is possible. His motive has no relevance to the question of whether it can be done.

Is it possible to strip the exif data from a jpeg? Sure, and I can show you how without knowing why someone might want to do it.

I ask why because I already know editing EXIF data in RAW files can be done. (I just did it above you there.) What I don't know yet is why and what he wants to change. If I know that info I could get more specific about how he could go about doing it.

IMHO why is probably the most important question. People assume they know the best way to do things, and ask questions about the detail. Sometimes they need to step back, tell us what they're trying to achieve, and maybe we can suggest a better overall method.

I really can't think of any reason someone would want to hide the exif in a raw. I hide the exif in my delivered images, but they're all jpeg. Anyone I give raw files to I trust enough that I don't care if they have the exif.

Mostly i'm just curious.